What websites have really cheap clothes for people on a budget?

My mom is making me buy my own clothes with my own money for school next year. When I say cheap I mean shirts being 5 maybe 10 or 15 bucks and pants like 20 maybe 30 bucks. Also I don't like real baggy pants. I think I'm a size 40. If its possible. Make sure the shirts have designs on them, not just a plain color. Thanks